Phosphonoacetic acid has been known for over fifty years now. It was only recently, however, that it was discovered that this compound was an antiviral agent exhibiting oral and topical activity against herpes simlpex infection. See in this regard the paper by Shipkowitz et al., Applied Microbiology 26, No. 3, 264 (1973).
It has also been found that phosphonoacetic is useful in combating Marek's disease in poultry. U.S. Pat. No. 3,836,650, issued Oct. 4, 1974.
The antiviral activity of phosphonoacetic acid may be due to the inhibition of the virus'ability to replicate when the compound is administered. This inhibition is believed due to the inhibition of deoxyribonucleic acid synthesis in the virus. See Overby et. al., Antimicrobial Agents and Chemotherapy, 6, No. 3, 360 (1974).